1. Field of the Invention
The invention relates to a cable routing structure.
2. Description of Related Art
A wide range of devices are mounted in a motor compartment of an electric vehicle, compared with a conventional engine vehicle. In terms of large devices, first, an electric motor for running (hereinafter, also referred to as “running motor”) is provided. Next, there is a power control unit (i.e., an inverter) that converts direct current (DC) output of a battery to alternating current (AC), which it then supplies to the electric motor. In addition, there is an auxiliary battery that supplies power to an auxiliary system (i.e., accessories), an electric compressor of an air conditioner, and a fuse box and the like. With a hybrid vehicle, an engine is also mounted in addition to the electric motor, in the motor compartment.
The term “accessories” refers to devices that are driven by voltage lower than the rated voltage of the running motor, and that are driven by the battery of a conventional engine vehicle. Typical accessories include a room lamp, a car navigation system, and power windows and the like. A control board in a power control unit that drives the running motor is also an accessory. Hereinafter, the power control unit will simply be referred to as “PCU”. Also, a battery that stores power for driving the electric motor will be referred to as the “main battery”, in order to differentiate it from the auxiliary battery.
Japanese Patent Application Publication No. 2010-264793 (JP 2010-264793 A) describes one example of a layout of devices in a motor compartment. JP 2010-264793 A illustrates a layout of a motor compartment of a hybrid vehicle, in which an engine and an auxiliary battery are arranged next to a PCU. Also, Japanese Patent Application Publication No. 2004-328870 (JP 2004-328870 A) describes an example in which an inverter is mounted above an electric motor. In JP 2004-328870 A, the inverter is fixed, via a gap, above the electric motor. The inverter is fixed above the motor by a fitting. Fittings that fix the inverter and the like are often referred to as brackets. In this specification as well, fittings for fixing the inverter and PCU will be referred to as brackets.
Many of the devices mounted in the motor compartment of an electric vehicle are electrical devices, and cables for transferring electric power and signals are connected to these devices. That is, more cables have to be routed in the motor compartment of an electric vehicle than have to be routed in the motor compartment (i.e., engine compartment) of a conventional engine vehicle. However, the power supplied from the PCU (i.e., the inverter) to the electric motor is high current, so it is better that the cables for connecting the PCU to the electric motor be short. Therefore, the PCU is arranged near the electric motor. This arrangement of the PCU may limit the cable routing structure. That is, several cables are connected to the PCU, but depending on the device layout around the PCU, it may be difficult to ensure the routing space for these cables. The technology described in this specification provides a preferable cable routing structure in a motor compartment.